Abstract: The light guide plate (LGP) with side lighting is effective to reduce the thickness of the display module and the number of the LEDlights. In order to obtain uniform surface illumination, a circle structure of light guide plate was introduced. Through deriving the rule of scattering netted dots, the distribution function for the size of scattering netted dots in light guide plate was obtained . Using VBA program, the scattering netted dots were generated in the CAD. Combined with the simulation software, it is verified that the luminance uniformity is more than 90% in the display area of guide plate, which meets the design requirements of back light module project.